Refrigeration



l Q G MUNTERS REFRIGERATION Filed March 29, 1929 Patented Apr. 18, 1933 UNITED STATES PATENT; OFFICE CARL GEORG MUNTEBS, OF STOCKHOLM, SWEDEN, ASSIGNOB T0 ELECTROLUX SEBVEL CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE BEFBIGERATION Application led March 29, 1929, Serial No. 350,845, and in Germany Hay 25, 1928.

My invention relates to refrigerator cabinets or the like, the refrigerating apparatus of which contains a pressure equalizing lnert gas circulating through the evaporator and absorber of the apparatus.

One purpose of my invention is provide such an arrangement of said refrlgeratmg apparatus and especially of its evaporator and cooling bodies thereof that the characteristic temperature conditions prevailing 1 n the apparatus are in an effective way utilized for the production of cold.

According to the invention two cooling units or bodies, one provided for the purpose of producing ice and the other one for cooling the air in the cabinet, are arranged on a common evaporator'shell in such a manner that, when the apparatus is fitted in the cabinet, the cooling unit provided for the purpose of producing ice is situated on the front end of said evaporator shell and facing the door of the cabinet, so that objects to be cooled, as, for instance, ice trays, arranged in said unit can be conveniently removed, while the cooling unit provided for the purpose of cooling the air in the cabinet is situated behind said cooling unit for the ice production. In the following description, said two cooling units are referred to as the ice producer and the air cooler respectively. The cooling units are so arranged on the evaporator shell that the evaporation of the refrigerant in the part of the evaporator taking up heat from the ice producer takes place at a higher partial pressure drop than in the part taking up heat from the air cooler.

The invention will be more fully described with reference to the accompanying drawing showing, by way of example, one embodiment of the invention and in which Fig. 1 is a vertical -section through a refrigerator cabinet with an absorption refrigerating apparatus mounted therein, arranged in accordance with the invention.

Fig. 2 is a front view ofthe ice producer, seei from the door opening of the cabinet an Fig. 3 is a section along the line III- HI in Fig. 1.

Referring more particularly to Fig. 1, refl erence character 10 designates the refrigerator cabinet provided with a front door 11 within which an evaporator 12 is arranged so as to extend into the insulated cooling chamber 13 from the rear wall 14 thereof. The evaporator 12 comprises a lengthened cylindrical vessel or shell, preferably of steel and arranged horizontally and parallel to a side wall of the refrigerator cabinet on which are mounted the ice producer 15 and the air cooler 16. Liquid refrigerant to be evaporated in evaporator 12 is supplied through conduit 17 and is distributed in said evaporator over distributing plates 18, 19 and 20. The upper plate 18 and the upper wall of the evaporator form a horizontal channel closed at its rear end and open at its front end, said plate being provided, approximately at its center, with a transverse rib 21 or the like and at its front end with another rib 22. Between these ribs 21 and 22 an overflow opening 23 is provided forthe refrigerant. A raised rim is provided around opening 23. The refrigerant forms a liquid pool on plate 18.

' Reference character 24"designates the generator which contains the refr1gerant or cooling agent, for instance ammonia; dissolved in a suitable absorption liquid, such as water. Although it is obvious that various substances may be used as cooling agent, ammonia is preferred but, in describing the appara-tus as using ammonia and specific related substances, it is to be understood that this is by way of example only and without limitation. Ammonia vapor is expelled from the solution in the generator and passes through conduit 25, the upper part of which forms a rectifier 26, into condenser 27 which consists of a water cooled coiled pipe, the

'end 17 of which enters evaporator 12 and liquid refrigerant consequently forms a liquid pool between ribs 21 and 22' and thereafter passes through opening 23 to the sec ond distributing plate 19 arranged below the l first one. Said plate 19 is provided at both ends with ribs 28 and 29 respectively and an overflow 30 at its rear end, the remaining part of liquid refrigerant passing through said overflow to the third plate 20 which is of a shape similar to that of the middle plate 19 except for the overfiow in this case being arranged at the front end of the plate.

From absorber 31 an auxiliary medium, as for example hydrogen, is conducted through gas heat exchanger 32 and conduit 33 and introduced in substantially pure state into evaporator 12 at its rear end, thence flowing through the upper channel, formed by plate 18 and the upper wall of the evaporator, towards the front end of same. The liquid ammonia collected between ribs 21 and 22 evaporates rapidly in the hydrogen whereby a low temperature is obtained in the front end of the evaporator and consequently in ice producer 15. The ice producer consists of a box-shaped metal cover arranged in a heat conducting relation to the front end of` evaporator 12. In a preferred form, shown more clearly in Figs. 2 and 3, the ice producer consists of two parts 34 and 35, preferably of metal plates, clamped to the evaporator shell b screws 0r bolts 36 and provided at their ree ends with inward bends so as to form special compartments 37 for receiving objects to be quickly cooled down as, for instance, ice trays or containers. If it is desired to increase the rate of cooling, it is advisable to insulate the ice producer as indicated in Fig. 3 by jacket 38 of heat insulating material, which preferably is unaffected by moisture. Further, a heat insulating filling 39, such as cork or the like, may be provided between said jacket 38 and the evaporator shell. Said insulating covers also can be inade removable so as to be applied only when an increased rate of ice productionis desired. Further, the ice producer may be so constructed that the ice containers directly contact the evaporator body when inserted in the iceproducer.

Then the hydrogen has been saturated with ammonia vapor to a certain extent, that is, when the rate of evaporation of the liquid refrigerant collected on plate 18 has decreased, the gas mixture flows from the front end of evaporator 12 through channels 40, 41 and 42 formed by plates 18, 19 and 20, the side walls and the bottoni wall of the evaporator to the rear end of same. The remaining part of liquid refrigerant collected on plates 19, 20 and in the lower part of the evaporator thereby evaporates, thus producing cold at a high-er temperature than 1n the first part of the evaporator. The enriched gas mixture leaves evaporator 12 and is led by gravity into heat exchanger 32 through conduit 43 and thence to absorber 31.

Due to the construction of the evaporator above described, the evaporation of the refrigerant in the part corresponding to the ice producer, that is, in the front part of the evaporator, takes place at a higher partial pressure drop than in the rear part of same and thus a lower temperature is obtained in the first mentioned part thereof.

As shown in the drawing, the air cooler 16, in this preferred embodiment of the invention, consists of metal anges 44 arran ed transversely on the rear portion of the cy indrical evaporator shell in a vertical or substantially vertical position permitting the air in the cabinet to circulate through the space formed between said flanges.

In the upper part of absorber 31, poor ammonia solution is introduced through conduit 45, part of which forms the outer conduit of a heat exchanger 46, the inner conduit 47 of which conducts rich solution from the lower part 48 of absorber 31 to chamber 49 forming an auxiliary generator. A flue 50 passes through chamber 49 and generator 24. A suitable source of heat, not shown in the drawing, as, for instance, an electric heating unit or resistance or a gas burner, is placed in the lower end of flue 50, which latter is arranged in a somewhat inclined position, whereby heat is transferred from said source of heat through the wall of flue 50 to chamber 49 and generator 24. Chamber 49 communicates with the upper part of generator 24 by means of conduit 51, the upper portion of which is made and arranged so as to form the upwardly extending vapor and liquid pipe of a thermo-Siphon through which ammonia solution is forced into generator 24 by means of ammonia gas expelled in chamber 49 and introduced into conduit 51 through gas conduit 52.

Having thus described my invention, what I claim is 1. In a refrigerator, a cabinet, a horizontally disposed evaporator shell in said cabinet, air cooling means on the rear part of said shell, ice freezing means on the front part of said shell, means for introducing an inert gas into the rear part of said shell, a plurality of vertically spaced horizontally disposed liquid distributing plates within said shell, a transverse rib on the central part of the uppermost of said plates, a conduit for conveying liquid refrigerant to said shell, said conduit entering the rear part of said shell and extending forward of said transverse rib and means for removing refrigerant and inert gas from the rear of said shell.

2. In arefrigerator, a cabinet, a horizontally disposed evaporator shell in said cabinet, air cooling means on the rear part of said shell, ice freezing means on the front part of said shell, means for introducing an inert gas into the rear part of said shell, a plurality of vertically spaced horizontally disposed liquid distributlng plates within said shell, a transverse rib on the central part of the uppermost of said plates, said uppermost plate contacting the interior of sa1d shell along the rear and side edges of the plate and forming a passageway around the front of said plate, the remaining lates contacting said shell along their side e ges and forming passageways around both ends of the plates, a conduit for conveying liquid refrigerant to said shell, said conduit entering the rear part of said shell and extending forward of said transverse rib and means for removing reflrligerant and inert gas from the rear of said s el 3. In a refrigerator, a cabinet having a door and a rear wall, a horizontally disposed evaporator shell supported by said rear wall air cooling means on the rear art of sai shell, ice freezing means on the ont part of said shell, a conduit extending through said rear wall for introducing an inert gas into the rear part of said shell, a series of horizontally disposed plates within said shell, a transverse rib on the central part of the uppermost of said plates, a conduit for conveying liquid refrigerant to said shell, said conduit extending within said inert gas conveying conduit and extending forward of said transverse rib and a conduit extending through said rearwall for conveying refrigerant and inert gas from said shell.

4; A refrigerating apparatus comprising a horizontally disposed evaporator shell, air cooling means on the rear of said shell, ice freezing means on the front of said shell, means for introducing an inert gas into the rear of said shell, and a conduit for conveying liquid refrigerant into said shell, said conduit entering said shell at the rear and extending to the more forward part of the shell, said ice freezing meanscomprising a pair of members each having an arcuate central portion' in contact with said shell and U-shaped end portions forming rectangular compartments for the reception of ice trays and bolts passing through said members to clamp their arcuate portion around said shell.

In testimony whereof I have affixed my signature.

VCARL GEORG MUNTERS. 

